A review of the prognostic role of cytogenetic, phenotypic, morphologic, and immune function characteristics in chronic lymphocytic leukemia

Recent reports of successfully completed cytogenetic studies using polyclonal B-cell activators demonstrate that trisomy-12 and 14 q+ are the most frequently observed chromosomal abnormalities in B-cell chronic lymphocytic leukemia (CLL). It appears that when trisomy-12 is accompanied by yet another abnormality, the prognosis of patients is uniformly poor. Patients in early stages of CLL retain delayed hypersensitivity reactivity, while those in advanced stages are usually anergic. The lymphocytes from venous blood of patients with CLL appear to retain at least some ability to respond to stimulation with mitogens in early stages, whereas in advanced stages they show no response to mitogens. Serum immunoglobulin levels are normal in the early (0 and I) stages, are markedly decreased in the advanced (III and IV) stages, and are somewhat between these extremes in the intermediate (II) stage of CLL. Prolymphocytic leukemia and prolymphocytoid transformation of CLL are indicators of poor prognosis, while a morphological variant characterized by large granular lymphocyte is associated with good prognosis. At this time it is not possible to ascribe strong prognostic significance to phenotypic features of lymphocytes in B-CLL; however, studies currently in progress may soon provide important insights on this subject. We have reviewed the pertinent literature and we also present a summary of results from our laboratory.     

Genetics of mosquitoes

Beginning in the mid-1950s, much progress has been made in studying various aspects of the genetics of mosquitoes, particularly involving several species of three principal genera,Aedes, Culex andAnopheles, that transmit important human diseases. Here I discuss selected areas of research involving formal genetics; genome structure, organization and evolution at the interspecific and intraspecific level; and evolutionary genetics of theAedes scutellaris group. Information and insights gained from in-depth analyses of these areas, particularly transmission genetics, cytogenetics and genetics of chromosomal rearrangements, and of mutagen-induced sexual sterility, have proved invaluable for the development of the theory and evaluation of feasibility of genetic control of natural populations. As a result, mosquitoes represent some of the best studied taxa at various levels of genetic organization. Recent developments in molecular genetics offer exciting possibilities for extension of these concepts.     

Interaction of constituent subunits in ribulose 1,5-bisphosphate carboxylase from Aphanothece halophytica

Ribulose 1,5-bisphosphate carboxylase-oxygenase (RuBisCO) from the halophilic cyanobacterium, Aphanothece halophytica, dissociates into catalytic core (large subunit A oligomer) and small subunit B under low ionic strength during sucrose density gradient centrifugation. Supplementation of KCl, NaCl, or K2SO4 ( [I] = 0.3 M) partly prevents the dissociation, the preventive effect of divalent cation salts such as MgCl2 and CaCl2 being more effective than monovalent cation salts. RuBisCO with its higher-plant-type molecular form can be isolated from the cyanobacterial extracts using gradient medium containing 0.3 M KCl, 20 mM MgCl2, and 10 mM CaCl2. The isolated enzyme contains large subunit A and small subunit B in a molar ratio of approximately 1:1, estimated from the densitometric scanning of Coomassie blue-stained gels. During the second sucrose density gradient centrifugation to remove minor contaminants, a small amount of subunit B is depleted from the holoenzyme. Determination of the molecular weight by equilibrium centrifugation and electron microscopic observation have confirmed that the cyanobacterial RuBisCO has an A8B8-type structure. The enzyme activity per se is found to be sensitive to concentrations of salts, and small subunit B is obligatory for the enzyme catalysis. It has been shown that the more the enzyme activity is inhibited by salts, the tighter the association of subunit B becomes. It is likely that the active enzyme retains the loose conformational structure to such an extent that the dissociable release of subunit B from the holoenzyme in vivo is not allowed.     

Multi-Sample Slippage Test for Ordered Observations

A multi-sample slippage test based on ordered observations has been given. The test statistic is based on the sum of ranks of the sample. The probability distribution of the test statistic has been worked out for small sample and it turns out to be chi-square distribution for large sample. The analytical procedure has been explained by a numerical example.     

Relationship of combined nitrogen sources to salt tolerance in freshwater cyanobacterium Anabaena doliolum

Higher concentrations of NaCl inhibit the growth and reduce the specific growth rate of the freshwater cyanobacterium Anabaena doliolum. Among the nitrogen sources tried, nitrate protected the cyanobacterial cells most from salt toxicity. However, supplementing of medium with nitrate could increase the adaptability of the cells at sublethal doses but it would not permit growth at otherwise lethal doses of 300 mmol 1^-1 NaCl. Nitrate uptake was proportionally related to the NaCl level in the medium. The uptake of sodium was minimum when nitrate was simultaneously available to the cells, indicating the interaction of nitrate with the Na⁺ carrier. Na⁺ efflux was maximum in N², ammonia, urea and nitrate in decreasing order. This led to the conclusion that Na⁺ influx plays the critical role in salt tolerance, rather than its efflux.